eMedicine Specialties > Radiology > Musculoskeletal

Neuropathic Arthropathy (Charcot Joint)

Author: Ali Nawaz Khan, MBBS, FRCS, FRCP, FRCR, Consultant Radiologist, North Manchester General Hospital, The Pennine Acute NHS Trust, Manchester UK
Coauthor(s): Muthusamy Chandramohan, MBBS, DMRD, FRCR, Consultant Radiologist, Bradford Teaching Hospitals, UK; Ian Turnbull, MB, ChB, MD, DMRD, FRCR, Lecturer, Department of Radiology, University of Manchester; Consulting Neuroradiologist, Hope Hospital, Salford, Manchester and North Manchester General Hospital, UK; Sumaira MacDonald, MBChB, PhD, MRCP, FRCR, Lecturer, Sheffield University Medical School; Endovascular Fellow, Sheffield Vascular Institute
Contributor Information and Disclosures

Updated: May 27, 2008

Introduction

Background

Neuropathic osteoarthropathy can be defined as bone and joint changes that occur secondary to loss of sensation and that accompany a variety of disorders. Charcot first described the relationship between loss of sensation and arthropathy in 1868.

The radiographic changes include destruction of articular surfaces, opaque subchondral bones, joint debris, deformity, and dislocation. Neuropathic arthropathy poses a special problem in imaging when it is associated with a soft tissue infection.^{1,2,3,4,5,6,7}

Pathophysiology

The pathophysiology of neuropathic arthropathy is debatable. The general consensus is that the loss of proprioception and deep sensation leads to recurrent trauma, which ultimately leads to progressive destruction, degeneration, and disorganization of the joint. Another theory postulates that neurally mediated vascular reflex results in hyperemia, which can cause osteoclastic bone resorption.

Causes of neuropathic arthropathy include the following:

• Diabetes⁸
• Use of steroids
• Alcoholism
• Trauma 
• Infection
• Amyloidosis
• Pernicious anemia
• Syphilis
• Syringomyelia
• Spina bifida
• Myelomeningocele
• Leprosy
• Multiple sclerosis
• Congenital vascular disease
• Charcot-Marie-Tooth disease
• Cord compression
• Asymbolia
• Connective disorders, such as rheumatoid arthritis and scleroderma
• Ehlers-Danlos syndrome
• Raynaud disease
• Adrenal hypercorticism
• Thalidomide embryopathy (congenital arthropathy in offspring of exposed mothers)
• Paraneoplastic sensory neuropathy
• Cauda equina lipoma

One of the joint manifestations of leprosy are the signs of Charcot's disease. Charcot's disease of leprosy advances despite treatment.⁹

Neuropathic osteoarthropathy can be classified into hypertrophic and atrophic types. Hypertrophic changes predominate in the upper motor neuron lesions, and atrophic changes occur in peripheral nerve injuries. The early stage of osteoarthritis simulates neuropathic osteoarthropathy, both radiologically and pathologically.

Progressive joint effusion, fracture, fragmentation, and subluxation should raise the suspicion of neuroarthropathy. In the advanced stage, abnormal findings on radiographs include subchondral sclerosis, osteophytosis, subluxation, and soft tissue swelling. Long-standing neuroarthropathy is characterized by disorganization of joints. The finding of considerable amounts of cartilaginous and osseous debris within the synovial membrane (termed detritic synovitis) should alert the pathologist that the changes may represent a neuropathic joint. Other causes of detritic synovitis include osteonecrosis, calcium pyrophosphate dihydrate crystal deposition disease, psoriatic arthritis, osteoarthritis, and osteolysis with detritic synovitis.

Frequency

United States

The overall incidence in the United States appears to be the same as that found internationally. Approximately 15% of patients with diabetes appear to have neuropathic arthropathy.

International

Neuropathic arthropathy is seen in 10-20% of patients with tabes dorsalis and in 20-25% of patients with syringomyelia.

Mortality/Morbidity

Mortality and morbidity are related to the disease process, the cause of the disease, and the related complications. Morbidity is worsened by the development of soft tissue infection and osteomyelitis.

Race

Diabetes-related neuroarthropathy appears to be more common in the Western population, whereas neuroarthropathy associated with infection, such as in tabes and leprosy, is common in developing countries. No racial predilection has been documented in steroid-induced neuropathic osteoarthropathy.

Sex

In general, no sex predilection has been recorded; however, neuroarthropathy related to connective tissue disorders, such as scleroderma, appears to be more common in females. Neuroarthropathy related to alcoholism and trauma is more common in males.

Age

Neuropathic arthropathy related to diabetes, syphilis, leprosy, and connective tissue disorders is more common in the elderly population. Neuroarthropathy related to asymbolia, spina bifida, and spinal trauma is more common in young individuals. Sensory impairment associated with spina bifida and myelomeningocele is the most frequent cause of neuropathic arthropathy in childhood.

Presentation

Joint changes usually precede neurologic deficit. The affected joint is usually swollen and warm but is not painful. Pain may be noted at presentation in one third of patients, but the response to deep pain and proprioception may be reduced.

Preferred Examination

Radiography may be the only imaging required. In the appropriate clinical setting, a fairly accurate diagnosis can be achieved. The roles of ultrasonography and CT are limited. Ultrasonography and CT can be helpful in identifying any local collection, and they can be used to guide aspiration cytology. The role of MRI and radionuclide scanning is to differentiate soft tissue infection from osteomyelitis.^10,11

Limitations of Techniques

Radiographic findings in the early stages may simulate osteoarthritis. Radiographs may not demonstrate findings that help in diagnosing osteomyelitis in neuropathic joints, which is a common problem.

The roles of ultrasonography and CT are limited. Ultrasonography can be used to identify any local collection when infection occurs and to guide aspiration for cytologic analysis; however, it provides no further information regarding the integrity of underlying bone. Although CT may be helpful in evaluating cortical destruction, sequestra, and intraosseous gas, these changes are not specific for neuropathic arthropathy.

The role of MRI and radionuclide scanning is to differentiate soft tissue infection from osteomyelitis. Bone marrow edema is nonspecific and has several causes; therefore, differentiating bone marrow edema from neuropathic arthropathy may not be possible on the basis of MRI findings alone. Similarly, enhanced bone activity on radionuclide scans is a nonspecific finding and may occur with several neoplastic, inflammatory, and degenerative processes.

Differential Diagnoses

Calcium Pyrophosphate Deposition Disease
Osteoarthritis, Primary

Other Problems to Be Considered

Osteoarthritis
Calcium pyrophosphate dihydrate crystal deposition disease
Osteonecrosis
Posttraumatic osteoarthritis
Infection
Alkaptonuria

In the early stage, neuropathic arthropathy can simulate osteoarthritis. Bone fragmentation and collapse are seen in osteonecrosis, posttraumatic osteoarthritis, intra-articular steroid injection, infection, and alkaptonuria.

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